This invention relates to apparatus for displaying information stored on film, and particularly to apparatus wherein an image on film is converted into a video signal for display on a video terminal.
Prior U.S. Pat. No. 3,753,240 discloses an apparatus useful for displaying images contained on film. The apparatus includes mechanical means for selecting a particular film, such as a micorfiche card, locating that film in the operative position of a video signal generator, so that the image on the film can be converted into a television-type video signal, and the video signal provided to a display for display of the information contained on the film. This type of system is particularly useful for retrieving information which is not easily reduced to alpha-numeric format. For example, a great deal of alpha-numeric data storage would be required to store the equivalent of individual's signature in conventional computer data storage equipment. This type of storage would require that the signature be encoded according to a code representing each segment of the signature, and its relative position with respect to the other segments of the signature. A large storage capacity woudl be required to permanently record this information in a computer system and make it available for relatively rapid display on a terminal in response to instructions by the operator of the computer.
Systems for storing information, such as photographs or signatures, on microfilm have been known for years, and provide a relatively economical storage medium, since the information does not have to be reduced to digital format. Conventional microfilm storage systems require that the system user manually retrieve the individual film or microfiche card from a file, and place it in a viewer in order to located and display the individual image which he desires to view. Prior U.S. Pat. No. 3,753,240 discloses a system wherein such image information is stored on microfiche cards, which can be automatically retrieved and positioned in the operative position of a video signal generator. The video signal generator then provides a television-type video signal representative of the microfiche image, and provides the signal for dispaly on a remote terminal.
This type of system is of particular advantage in applications wherein it is necessary to retrieve one of a large number of images from a file within a relatively short period of time. For example, when a customer presents a check for payment at a bank, it is desirable that the bank teller check the signature on the check against the signature of the banking customer which is on file. Typically, this requires that the teller leave his position, go to the central file, locate the card, compare the signature on the card with the signature on the check, return the card, and then return to his counter position to complete the transaction. In accordance with the prior patent, it is envisioned that a cathode-ray terminal at the teller's counter location can be provided, which will display a microfilm sorted image of the customers's signature in response to the teller's command, consisting of, for example, the customer's account number. Thus, much time and effort can be saved and the temptation to pay a check without verifying the signature is avoided.
The system disclosed in the prior patent has several disadvantages which make it difficult to implement the system in a practical environment. In particular, the prior system may experience difficulties in mechanical card retrieval. Also, it may not be able to adapt to microfilm images having different quality levels, because of photographic processing changes, and therefore different film density values for signature and background. Further, the prior art system makes no provision for handling microfilm images having different polarities. The prior system is adapted to provide only a single video image at any time. Therefore, in a bank with many tellers, it will be necessary for one teller to complete viewing a particular signature before another teller can have access to the system to view a different signature. While the prior system does provide for the possible provision of a marker image in each image frame to facilitate the alignment of raster scanning patterns with the frame, it is possible in accordance with the prior system that the frame image itself can interfere with the automatic operation of the electronics which locates the marker image and aligns the raster in accordance with the marker location. In addition, the prior system makes no provision for the possibility of there being multiple images on each frame of the micorfiche. In this case, it is desirable to change raster size in orde to provide a large dispaly of the desired individual image, by itself. It is also advantageous to blank portions of each frame which contain information other than that to be displayed. This avoids operator confusion. The prior system also makes no provision for rotation of the raster pattern of the image detecting system so that the raster pattern can be aligned with the actual orientation of the image on the film.
It is an object of the present invention to overcome these and other disadvantages of the prior system and to provide a complete and practical system for the rapid display of image information stored on microfilm or other film storage medium, in a system controlled by computer generated signals.